Archive for January, 2011

Climate change in the Uxbridge Gazette

January 19, 2011

I was contacted earlier this month by a local paper doing a feature on the recent cold weather. I gave a few quotes and I think it turned out ok! Here’s the text from the article (it’s not online):

Last December was the coldest in the UK since records began, with the local weather station at RAF Northolt seeing its lowest-ever temperature. So why was 2010 among the hottest years globally? Reporter James Cracknell asks a top climate scientist from Brunel University.

Climate change is never far from the news and is a major concern, not just for environmentalists, but for anyone involved in planning and preparing for our future. Yet the science can seem complicated and confusing for many of us.

This is especially so when we look outside and see nearly a foot of snow, as Hillingdon residents did last month.

The Met Office have confirmed it was the coldest December in the UK since records began in 1910 and that a record low for the borough of minus 14.2C was set at RAF Northolt on the night of December 19/20.

How does this fit in with climate change, which we are told will cause average temperatures to rise rapidly unless the dangerous greenhouse gases released from burning oil, gas and coal, can be dramatically reduced?

The latest global figures show that 2010 as a whole was actually one of the hottest ever on record, despite the bitter winter seen in northern Europe. Climate scientists from the University of Alabama in Huntsville have reported that only 1998 – when world temperatures were boosted by a strong El Nino event – was hotter than 2010. And only by 0.01C.

Brunel University’s own expert, Dr Andy Russell, who lectures on the Climate Change Impacts and Sustainability masters course, told the Gazette: “The first thing to say is that a couple of cold winters in Europe do not mean that global warming has ended.

“We try to understand long-term changes over the whole planet – you can’t learn much by looking out of the window every now and again.

“Similarly, we also need to consider more than one season on one continent. Taking this view, we see that Russia, North Africa, Antarctica and the Arctic were much warmer than usual this year.

Dec 2009 to November 2010 temperature differences from the 1951-1980 average from NASA GISS. There is sparse data coverage over the poles.

“When we work out the global average temperature for 2010, the European cold snap doesn’t come close to cancelling out those warming areas.

“Even the cooling seen over the Pacific Ocean in the last few months – a natural pattern known as La Nina – has failed to make much of an impact on the warming trend.”

But if the world is warming, why is it still so cold in the UK? “Oddly enough, it could be caused by the intense warming that we’ve seen in the Arctic in recent years,” explained Dr Russell.

“Some new research using computer models of the climate has shown that the melting of the Arctic ice has changed the wind patterns over a region reaching all the way down to Europe. Where our winters used to be bathed in relatively warm winds from the west, we now experience bitter winds from the east.”

The Brunel University course teaches students about the potential impacts of man-made climate change across key areas including health, business, politics and technological development.

Recent severe weather events such as the floods in Australia, devastating wildfires in Russia and record monsoon rains in Pakistan should become more common and present a major challenge for the authorities tasked with preparing for and coping with these disasters.

While forecasting the weather remains difficult, Dr Russell says the one thing we know to expect is the unexpected.

“As we continue to experiment with our atmosphere by adding more greenhouse gases, we should probably be prepared for more climate surprises like this one,” he warns.

Useful climate tools and data sites

January 11, 2011

Here are some links to useful climate data/tools. There’re my favourite places to get simple data.

If anyone uses anything different, please leave let me know!

KMNI’s Climate Explorer – excellent tool to get loads of data and basic plots. I’ve always found the inface friendly too.

NASA’s GISS Surface Temperature Analysis (GISTEMP) – raw station data and nice plotting tool.

UEA’s Climatic Research Unit have lots of data but no plotting tools.

Daily Earth Temperatures from Satellites – if you want satellite derived temperatures from various levels, this is the place to go.

NOAA’s National Climatic Data Centre – looks like there’s lots there but I’ve never really looked through it.

The University of Wyoming’s weather balloon data – probably a bit niche for this list but this is an amazing archive of balloon data from all over the world! Surely you need to check just how strong the Antarctic inversion is today? No?

Why has this winter been so cold in Europe?

January 6, 2011

This post was chosen as an Editor's Selection for ResearchBlogging.orgI’ve written a couple of posts recently looking at the cold UK weather in context and how snow forms.

What I haven’t done, though, is looked at why it’s been so cold over Europe this winter (as well as last year’s winter).

It just so happens that a paper came out in the Journal of Geophysical Research recently (Petoukhov and Semenov, 2010) that might hold the answer.

They looked at whether changing the sea ice concentration in a particular area of the Arctic (the  Barents-Kara sea) in a long run of a climate model changed the conditions over Europe.

Their reason for doing this was that the very cold winter of 2005/06 was accompanied by very low sea ice in this region – they don’t mention 2009/10 and 2010/11 at all, though, as they would have been writing the paper before these cold European winters occurred.

To isolate the effect of the sea ice in this one region they use a mean state (a “climatology”) for most of the planet in the model but change the amount of ice on the  Barents-Kara sea. The results are quite surprising.

The winter wind patterns over Europe change dramatically when they changed the ice concentration from 80-100% to 40-80%. You can see this in the figure below, which is from the paper but I’ve highlighted the key areas on the wind plot and removed some of the panels.

Mean surface air temperature and 850 hPa wind anomalies for February from the model runs using 2 ice scenarios.

(When they set the sea ice close to 0%, Europe goes into a different state that is similar in temperature to the 80-100% case.)

So why does Europe get cold in a model world where the Barents-Kara sea has 40-80% sea ice concentration? In this model run, the result of this level of sea ice is to set up a big anti-cyclonic (high-pressure) anomaly over the pole. In the northern hemisphere air rotates clockwise around a high so this explains the switch in wind direction that drives the change over Europe. However, the hypothesis they present as to why the sea ice change leads to a high pressure anomaly over the pole is not straightforward and probably deserves a bit more study.

So, in essence, this all seems to be saying that it’s climate change that has led to our very cold winter! I can imagine some people finding that hard to swallow but here’s a quote from the paper that sums it up better than I just have:

Our results imply that several recent severe winters do not conflict the global warming picture but rather supplement it, being in qualitative agreement with the simulated large-scale atmospheric circulation realignment.

Anyway, all interesting stuff and I look forward to seeing some more analysis, especially a better climatology of winter temperatures in Europe and Arctic sea ice to see if that fits in with this hypothesis and a better physical model for the different changes linked with different sea ice concentrations.

UPDATE (10th Jan 2011): I just read someone claiming to have “debunked” this paper by showing that sea ice concentration and European temperature don’t correlate. However, this completely misses the non-linearity of the relationship. I think it’s fine to question the findings of the paper but I suspect that to “debunk”, or verify, the findings using the actual sea ice and temperature measurements you’d have to pick apart the contributions of other factors (e.g. polar jet changes, ENSO teleconnections) and then find some way of characterising the non-linear nature of the relationship with B-K sea ice.

ResearchBlogging.orgV. Petoukhov, & V. A. Semenov (2010). A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents Journal of Geophysical Research, 115 : 10.1029/2009JD013568

My blogging review of 2010

January 4, 2011

So, it’s 2011. Time for a quick look back at the first whole year of my blog.

Surprises

Well, I’m shocked at how many people have read and commented on my blog. I thought I’d be writing mostly for friends and colleagues but the blog seems to have reached a little further. If anyone reads regularly or just wants to say hello, I’d really like to hear from you; please leave a comment to let me know who you are and if there’s anything you think I should be writing in 2011. (And thanks for reading!)

The other big surprise was being linked to and quoted in a Guardian article about the Institute of Physics. I only knew about it when I was reading the paper in a cafe and noticed my name in the paper!

I also wasn’t expecting the response to my “Hockey Stick” post, which I wrote mostly for my own benefit to have all the IPCC climate reconstructions in one place. I’ve been meaning to write a review of the Hockey Stick book (by the Bishop Hill guy) but haven’t quite found the time.

That leads nicely on to the next point…

Networks

I’ve not actually been reading climate blogs for that long, probably 2 years or so. I’d like to spend more time reading and commenting but there just aren’t enough hours in the day.

Anyway, here’s what I’ve noticed in that time and it’s probably not very shocking.

There seem to be two, shall we say, very passionate groups/sides of bloggers. I guess you’d group them as pro “established climate science” or against. I quite often see the same names commenting on the same “sides”. It’s all quite cliquey and often impolite (to say the least). Maybe I should look into this more and think of a way of analysing it but this isn’t really the time to do it.

The point I want to make now is about my blog. Some of the days when I’ve got lots of hits/comments are when I’ve been linked to from one of the bigger blogs and, by the nature of those comments, it’s not difficult to tell which “side” that link has come from!

I’m actually quite glad I’ve not been blogging long enough (or comment around enough) to have been drawn in to one of these well-defined cliques – I’m happy enough to just be writing about what’s interesting me rather than feeling an allegiance to a particular cause.

Top Posts

According to WordPress, these are my posts that got the most views in 2010.

1

Dear Institute of Physics… March 2010
62 comments

2

The “Hockey Stick” evolution June 2010
104 comments

3

Britain’s snow and climate change January 2010
1 comment

4

Antarctic climate change – the exception that proves the rule? March 2010
10 comments

5

Skepticism or denial? February 2010
20 comments

(I’m surprised that the snow post is in there. I think it must have googled a lot recently!)

Anyway, thanks again for reading and hope to see you here in 2011.